Marpaung, J. H. ., and N. Tarigan. “Analysis of Palm Caul, Bark and Palm Sheel Fuel Use in Multi-Fuel Boiler Systems at PT. Toba Pulp Lestari, Tbk Porsea”. IRA Jurnal Teknik Mesin Dan Aplikasinya (IRAJTMA), vol. 2, no. 3, Dec. 2023, pp. 1-7, doi:10.56862/irajtma.v2i3.67.